The tired, dazed feeling you have after spending the day outdoors on a very sunny day, usually at a park or the beach.

It feels like your brain is filtering incoming information through molasses. It usually takes a few seconds for you to understand what people are saying to you. Also carries the overwhelming desire to nap.

DAN: Wanna get something to eat?

JOHN: (after a long pause) Were you just talking to me? Sorry, I'm sun stupid. What was that again?